1. Field of the Invention
This invention relates to dispenser caps of the type intended to discharge viscous products in ribbon or strip-like form.
2. Description of the Related Art Including Information Disclosed Under 37 CFR .sctn..sctn.1.97-1.99
The present invention more particularly relates to improvements in the dispenser cap illustrated and described in U.S. Pat. No. 5,044,530 dated Sep. 3, 1991, and issued to co-inventor Gene Stull.
The following additional U.S. patents are cited as being of interest in the field to which the present invention pertains:
U.S. Pat. Nos.:
______________________________________ 1,895,854 3,108,721 3,216,630 3,285,479 3,369,707 3,549,060 3,578,223 3,901,410 4,358,031 4,646,949 4,754,899 4,842,169 ______________________________________
Also, reference is made to:
British Pats. Nos. 10,767 and 688,732, and
German Pat. No. 1,203,668
U.S. Pat. No. 1,895,854 discloses a dispenser tube having an apertured cap which is turnable on the tube and wherein an internal plug that is carried on a helical member (29) advances toward or retracts from the aperture as the cap is turned, so as to selectively seal or open the aperture.
U.S. Pat. No. 3,108,721 illustrates a removable valve assembly for a container, having a plug-like valve stem which normally maintains the valve in a closed position. U.S. Pat. Nos. 3,901,410 and 3,549,060 similarly show plug-like tilt valves for selectively sealing off the discharge passages of pressurized aerosol containers.
U.S. Pat. No. 3,578,223 discloses a squeeze bottle having an apertured screw cap and an internal fitment member that is snapped onto and retained by the neck of the bottle. Unscrewing of the cap unseats a sealing peg from the aperture in the cap, to enable dispensing of product.
A somewhat similar construction is shown in U.S. Pat. No. 4,358,031. An apertured screw cap is carried on the neck of a bottle, and an internal fitment member having a sealing plug is receivable in the aperture of the cap.
U.S. Pat. No. 4,646,949 illustrates still another type of screw cap employing a sealing plug that is carried on the base cap or undercap for a dispenser. An aperture in the screw cap is selectively sealed off by the sealing plug when the screw cap is disposed in a lowered, sealing position.
British Patent No. 10,767 discloses an apertured closure cap for the threaded neck of a container, the latter carrying an upstanding stopper plug of flattened configuration. The plug is turnably mounted in a transverse wall that extends across the neck. As the cap is unscrewed, it backs away from the plug thereby to unseal the aperture in the cap.
British Patent No. 688,732 discloses a screw cap construction wherein an axially shiftable apertured closure cap is selectively sealed by a plug that is pressed into the neck of a container and held captive therein. When the cap is unscrewed, the plug is withdrawn from the aperture, enabling discharge of the contents of the container to occur.
German Pat. No. 1,203,668 discloses a twist cap construction employing a stopper peg that is carried by an insert which is force fitted into the neck of a container or tube, and an apertured closure cap that can be moved between sealing and discharging positions. The discharging position corresponds to a raised condition of the closure cap wherein its aperture is uncovered.
Also, U.S. Pat. Nos. 3,216,630; 4,754,899 and 4,842,169 disclose twist cap constructions of the type having stopper pegs of cylindrical configuration. The pegs in each case provide a seal with corresponding cylindrical walls of the discharge openings in the respective twist cap when the latter are placed in sealing positions.
In prior caps having round discharge passages, where the product being dispensed is relatively viscous as in the case of ketchup or mustard, such product emerges in the shape of an elongate, thin bead. In use, the container is inverted and squeezed while the opening of the twist cap is positioned over or applied to the underlying food.
As noted above in connection with U.S. Pat. No. 1,895,854 and British Pat. No. 10,767, efforts have been made to provide cap structures with elongated or oblong openings, in which the product is discharged as a flat ribbon, as opposed to a bead of essentially round or oval cross section. Such a ribbon shape has been considered desirable for use with mustard and ketchup, since it results in a more uniform application, and improved adhesion to the particular food to which such mustard or ketchup is being applied.
However, most prior attempts to achieve ribbon-type discharge characteristics have met with little commercial success. For example, in U.S. Pat. Nos. 3,285,479 and 3,369,707 the twist caps that are disclosed are provided with slit-like openings in their ends, in which are received blade-like sealing members. The blade-like members are fixedly mounted on the undercap or base cap. In U.S. Pat. No. '707, as the twist cap is unscrewed it rides up cam tracks provided on the base cap. The blade-like sealing member occupies the slit in the twist cap. During such unscrewing the upper end portion of the blade-like sealing member is forcibly twisted and deformed, and eventually separates from the walls of the slit to provide a discharge passage for the product. Following use, the consumer reseats the twist cap by turning it in a screwing-on direction, with the blade-like sealing member purportedly being restored to its initial planar shape, and re-establishing its position occupying the slit in the twist cap.
In U.S. Pat. No. 3,285,479 the arrangement is similar, except that the twist cap is not raised by means of a cam track on the base cap. Instead, when the twist cap is turned in either direction, the blade-like sealing member becomes deformed as it is engaged by the inner conical surface of the twist cap and the latter is in turn, cammed upwardly by such engagement. Portions of the walls of the slit become disengaged from the blade-like sealing member and thus enable product discharge. Re-sealing is accomplished by merely pushing downwardly on the twist cap. As this is done, the blade-like sealing member tends to restore the twist cap to its original circumferential position, and the walls of the slit slide over the upper end of the blade-like sealing member, to re-establish the seal.
A number of specific problems have occurred with dispensers of the type involving deformable stopper blades as described above. In particular, it is considered difficult to fabricate a solid sealing member in the form of a flat blade having sufficient resiliency so as to not take a "set", especially following an extended period of use. In addition, attempts to make a plastic blade relatively stiff often resulted in the blade cracking or breaking during use, as opposed to merely flexing, as was desired. In the event of such breakage, the sealing function of the dispenser was completely lost, and there was the possibility of plastic fragments finding their way into the dispensed product. This was particularly troublesome where the substance being discharged was a food such as mustard, ketchup or other creamy substance, such as dressings and the like.
Even where breakage of the blade did not occur, smooth operation of the cap was difficult to attain. In particular, the use of the blade as a cam to shift the cap, as in U.S. Pat. No. '479, caused undue stresses on the blade, and it is believed that the design parameters inherent in prior blade type sealing caps did not lend themselves toward adaptation to a smooth and reliable operating mechanism for a dispensing cap.
As noted above, the present invention involves improvements in the ribbon-type dispenser cap construction of Stull U.S. Pat. No. 5,044,530. While the devices disclosed in this patent have been found to be smooth and reliable in operation, efforts to reduce cost and assembly time are always considered of extreme importance. This patented cap involved basically three separate components, namely the cap body, the closure cap, and as a separate piece, the stopper blade. It was considered that if one component could be eliminated as a separate molded piece, considerable cost savings could be realized. Of course, additional criteria had to be met, namely that any resultant construction have the inherent reliability, safety from contamination, and ease of use of the patented device.